package demo.websocket.hyl;
import java.io.IOException;
import java.util.Set;
import java.util.concurrent.CopyOnWriteArraySet;
import java.util.concurrent.atomic.AtomicInteger;
import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;
@ServerEndpoint("/chat")
public class ChatEndpoint {

    private static final String GUEST_PREFIX = "游客";
    private static final AtomicInteger connectionIds = new AtomicInteger(0);
    private static final Set<ChatEndpoint> connections
            = new CopyOnWriteArraySet<>();

    private final String nickname;
    private Session session;

    public ChatEndpoint() {
        nickname = GUEST_PREFIX + connectionIds.getAndIncrement();
    }

    @OnOpen
    public void start(Session session) {
        this.session = session;
        connections.add(this);
        String message = String.format("* %s %s", nickname, "进入聊天室.");
        broadcast(message);
    }

    @OnClose
    public void end() {
        connections.remove(this);
        String message = String.format("* %s %s",
                nickname, "离开聊天室");
        broadcast(message);
    }

    @OnMessage
    public void onMessage(String message) {
        // Never trust the client
        // TODO: 过滤输入的内容
        broadcast(message);
    }

    @OnError
    public void onError(Throwable t) throws Throwable {
        System.out.println("错误: " + t.toString());
    }

    private static void broadcast(String msg) {
        for (ChatEndpoint client : connections) {
            try {
                synchronized (client) {
                    client.session.getBasicRemote().sendText(msg);
                }
            } catch (IOException e) {
                System.out.println("错误: 向客户发送信息失败");
                connections.remove(client);
                try {
                    client.session.close();
                } catch (IOException e1) {
                    // Ignore
                }
                String message = String.format("* %s %s",
                        client.nickname, "离开聊天室.");
                broadcast(message);
            }
        }
    }

}
